Square Enix have updated their official Kingdom Hearts blog to explain a newly announced feature in Kingdom Hearts 3D: Dream Drop Distance. As you can see from the screenshot below (click for a larger image), the game will feature a "Memoirs" section that will summarize the Kingdom Hearts series and present the information chronologically. This will help people to understand the game if they have not played some of the previous games.

In MEMOIR, you will be able to check the tutorial as often as you want and get various reflection-scenes of the story as you advance through the game. You will also be able to see your game progress in this menu.

Furthermore, in CHRONICLE you will be able to see the explanation of the past series, and therefore, those who are playing Kingdom Hearts for the first time will be find a summary of the story and be able to enjoy the game even more.